New majority governments in Canada tend to get re-elected the first time. It's just what happens. Justin Trudeau and the Liberals will go into the 2019 campaign as pretty big favourites. But what if they're vulnerable? Andrew Scheer and the Conservatives believe they have a secret weapon—a new campaign manager who has successfully run an underdog campaign by focusing relentlessly on one issue.

Are Hamish Marshall and the carbon tax the perfect combination to beat the odds and topple the Liberals after a single term? Who is the guy tasked with driving the point home to Canadians? And what does Trudeau have up his sleeve if the punches start landing? We're about a year out from a critical election. Maclean's senior writer Paul Wells breaks down the looming heavyweight fight.